Elia relies on the ARPs (Access Responsible Party) to maintain balance in its control area. Specifically, each ARP is individually responsible for the quarter-hourly balance of offtakes and injections in its portfolio or balancing perimeter.
Using metering and nomination data Elia checks, every quarter of an hour, that the access responsible parties (ARPs) are maintaining their balance. If an imbalance is found in the balance perimeter of an ARP between total physical injections, import and purchases on the one hand and total off-takes, export and sales on the other, imbalance tariffs are applied: "Tariff for maintaining and restoring the individual balance of access responsible parties". These tariffs are calculated based on the applicable balancing mechanism.
If an ARP's nominations are not balanced, an ‘external inconsistency’ occurs. If the external inconsistency is accepted by Elia, the imbalance tariff also applies, in accordance with the ARP contract.
Present imbalance price and imbalance price history
With regard to offtakes measured at the access points and distribution offtake positions (if it is a net offtake), a loss percentage is added to the balancing perimeter in accordance with articles 161 and 162 of the Technical Regulations for Transmission.